Investigating the effects of different electrodes on Al6061-SiC-7.5 wt% during electric discharge machining
Investigating the effects of different electrodes on Al6061-SiC-7.5 wt% during electric discharge machining
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DOI：
10.1007/s00170-018-2694-2
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
M. Raza;A. Wasim;M. Ali;S. Hussain;M. Jahanzaib
中科院分区：
文献类型：
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作者：
M. Raza;A. Wasim;M. Ali;S. Hussain;M. Jahanzaib
本研究旨在研究不同电极对挤压铸造Al6061-SiC-7.5wt%复合材料电火花加工性能的影响。采用铜、黄铜和不锈钢电极，研究了电流强度、脉冲宽度和占空比三个最重要的输入参数对材料去除速率(MRR)、表面粗糙度(Ra)和电极磨损率(EWR)的影响。为了改善加工性能，在介电液中污染了4wt%的石墨烯纳米颗粒。采用基于中心复合设计的响应面方法(RSM)进行实验设计和数学模型的建立。分别用方差分析和验证性检验验证了所建立的数学模型的充分性和有效性。对于多响应优化问题，采用期望函数法确定最优输入参数。对于所有电极，观察到电流强度是影响MRR、Ra和EWR的最重要的输入参数，其次是脉冲持续时间和占空比。对比分析表明，黄铜电极是MRR和Ra的较好选择。另一方面，不锈钢被确定为EWR的更好替代品。在以铜为参照物的情况下，黄铜电极的MRR比不锈钢电极高23.2%，表面光洁度比不锈钢电极低35.3%和32.3%。与铜相比，不锈钢电极和黄铜电极的EWR分别降低了25%和45.5%。多响应优化得到了加工Al6061-SiC7.5%复合材料的铜电极、黄铜电极和不锈钢电极的复合优选率分别为81%、78.8%和77.1%。
This research aimed to investigate the effects of different electrodes on the performance of electric discharge machined Al6061-SiC-7.5 wt% composite fabricated by squeeze casting process. The effects of three most significant input parameters including current intensity, pulse duration, and duty cycle on material removal rate (MRR), surface roughness (Ra), and electrode wear ratio (EWR) were investigated using copper, brass, and stainless steel electrodes. To improve the machining performance, graphene nanoparticles (4 wt%) were contaminated in dielectric fluid. Response surface methodology (RSM) based on central composite design was employed for design of experiments and development of mathematical models. Adequacy and validity of developed mathematical models were verified by ANOVA and confirmatory tests respectively. For multi-response optimization, desirability function approach was used to identify the optimum input parameters. For all electrodes, current intensity was observed as the most significant input parameter influencing MRR, Ra, and EWR followed by pulse duration and duty cycle. Comparative analysis revealed brass electrode as better option for MRR and Ra. Stainless steel, on the other hand, was identified as a better alternative for EWR. While taking copper as reference, 23.2% higher MRR and 20.3% better surface finish were achieved through brass electrode as compared to stainless steel electrode which provided 35.3% and 32.3% less MRR and surface finish respectively. EWR for stainless steel and brass electrode decreased by 25% and increased by 45.5% respectively with reference to copper. Multi-response optimization yielded compound desirability of 81%, 78.8%, and 77.1% for copper, brass, and stainless steel electrodes respectively for the machining of Al6061-SiC-7.5 wt% composite.